Sanders won applause for Medicare for All from the group on TV. But calling Trump a 'pathological liar' won't win over the larger Fox News audience.

Left, right, left, right: The political pendulum swings back and forth in America. George H.W. Bush gave way to Bill Clinton, who gave way to George W. Bush. Bush was succeeded by Barack Obama, who was succeeded by Donald Trump. If this kind of past is prologue, then Donald Trump will be replaced — in either 2021 or 2025 — by someone on the left.

And you can’t get much further left than Bernie Sanders, the feisty, white-haired septuagenarian and democratic socialist who ventured into enemy territory, aka Fox News, for a town hall Monday night in Bethlehem, Pennsylvania.

“Not everybody thought I should come on this show,” the Vermont senator told hosts Bret Baier and Martha MacCallum. No kidding. The Democratic Party is refusing to hold any of its 12 primary debates on the network. Kudos to Fox for inviting him and kudos to Sanders for accepting.

It’s unlikely that any Fox viewers will ditch Trump for the Sanders camp. Sanders, after all, said he disagrees with pretty much everything the president stands for. He called Trump “dangerous,” adding that “I don’t think the American people are proud that we have a president who is a pathological liar.” I’m betting that clip won’t show up on “Fox & Friends,” which regularly serves up Trump’s morning nourishment of sycophancy and bootlicking.

Sen. Bernie Sanders at a Fox News town hall with Bret Baier and Martha MacCallum on April 15, 2019 in Bethlehem, Pa.(Photo: Matt Rourke, AP)

But Sanders and Trump actually do have some things in common. As a congressman nearly 30 years ago, Sanders voted against the North American Free Trade Agreement, that Trump campaigned against and said he'd fix (he tweaked it and renamed it the U.S.-Mexico-Canada Agreement, and Sanders says it's not good enough). Sanders also opposed the Trans-Pacific Partnership from which Trump withdrew, and he opposed normalizing trade ties with China. In 2016, Trump proved that trade is an issue with traction, particularly in the Rust Belt. Sanders thinks he can do even better.

A health care surprise in a Fox News setting

Sanders also got traction — and dealt his Fox hosts a surprise — on health care. Baier asked the audience, which he said was politically diverse, if they would be willing to give up their private insurance for government health care. Lots of hands went up, and the room erupted in cheers. That probably wasn’t what Baier figured would happen.

Sanders pressed his advantage, asking a member of the audience why anyone should be satisfied with the U.S. spending so much more per capita on health care than other advanced nations — yet getting so little in return. “Thirty million people have zero health insurance,” he pointed out. He forgot to mention that Republicans have spent a decade whining about Obamacare, while failing to come up with anything better. Republicans even controlled the House, Senate and White House between 2017 and 2019, a golden opportunity, but did nothing. Anyone who thinks they’ll come up with something in 2021, as Trump now vows, well, keep sipping that orange Kool-Aid.

The reaction was more predictable when Sanders refused to condemn abortions that occur right up to the moment of birth. He said they’re rare (which really isn’t the point), and should be between “a woman and her physician, and not the government.” For that he got a few jeers.

No apologies for being rich

Hours before his Fox appearance, Sanders tweaked Trump by releasing 10 years of tax returns. Trump has famously stonewalled on releasing any of his, claiming (falsely as usual) that he can’t release them while under audit. Sanders’s adjusted gross income last year was $561,293, after raking in more than $1 million in both 2016 and 2017 — pretty good for a democratic socialist — and, when pressed about the fact that he was wealthy, he sounded just like the rich guys he likes to attack:

"This year, we had $560,000 in income," Sanders said. "In my and my wife's case, I wrote a pretty good book. It was a bestseller, sold all over the world, and we made money. If anyone thinks I should apologize for writing a bestselling book, I'm sorry, I'm not gonna do it.”

Then he turned the tables: “Why don't you get Donald Trump up here and ask him how much he pays in taxes? President Trump watches your network a little bit, right? Hey President Trump, my wife and I just released 10 years. Please do the same.”

Too old? 'Follow me around'

MacCallum seemed to toss everything but the kitchen sink at Sanders, trying again and again to nail him for something, anything, just one slip, pretty please? He swatted her away like a gnat on a hot summer night. In fact, for a guy born three months before the Japanese bombed Pearl Harbor (that’s 1941 for the history-challenged), Sanders seemed as mentally agile as any other candidate. Questions about his age — he would be 79 on Inauguration Day 2021 — are legitimate. Asked if he was up to the job, Sanders said simply, “follow me around the campaign trail."

That was a good answer, but I’m not sure Americans would really elect someone about to enter his ninth decade of life, no matter how spry he appears to be. On the other end of the age range, I’m not sure they’d elect a guy who looks like he still gets carded buying booze, either. No disrespect to either Sanders or the latest entrant into the Democratic free-for-all, 37-year-old Pete Buttigieg, but perhaps a Goldilocks candidate — not too old, not too young — would be just right.